The present invention relates to a composition containing one or more rubber reinforced thermoplastic resins and one or more thermoplastic norbornene resins, and further to shaped articles thereof, which exhibits good visibility of printed areas and excellent marking adaptability by irradiation of laser beams.
Rubber reinforced thermoplastic resins represented by ABS resins are excellent in their strength and processability, so that they have widely been used for various applications as shaped articles.
As to shaped articles, designs such as letters, symbols, patterns and pictures are printed on surfaces thereof by tampon printing or silk-screen printing, and such shaped articles have been used for various applications. However, these methods have problems such as poor printing caused by scattering of ink, and difficulty of printing on uneven areas and printing of minute letters. Further, when consideration is given to recycling of shaped articles on which the designs are printed by tampon printing or silk-screen printing, it is necessary to recycle shaped articles after removal of printed areas. With respect to recent market needs toward recycling and environmental correspondence, methods of doing printing with lasers have been employed.
However, when the rubber reinforced thermoplastic resins such as ABS resins are applied to applications which are used in fields requiring heat resistance and used for laser marking, they have problems that the degree of color development and the clarity of letters or symbols are insufficient.
On the other hand, as thermoplastic norbornene resins, there have been known addition (co) polymers of norbornene derivatives and ring-opening (co)polymers of norbornene derivatives. These thermoplastic norbornene resins have good optical properties, low moisture absorption and excellent heat resistance, so that applications thereof in various fields have been expected.
However, thermoplastic norbornene resins have disadvantages of low impact resistance and poor toughness. Japanese Patent Laid-open Publication (Sho) 57-3701 discloses that rubber polymers are mixed with norbornene resins for overcoming these disadvantages. However, the sufficient effect can not always be obtained, and other properties thereof are rather deteriorated in some cases.
Recently, needs of durability under hard conditions such as high temperature and humidity to resin materials become strong, so that new resin materials which have not only good mechanical properties and adaptability for laser marking, but also excellent durability under hard conditions.
The present inventors have conducted intensive investigation on above-mentioned problems. As a result, the inventors have discovered that a thermoplastic resin composition which have excellent heat resistance, strength, toughness, processability and adaptability for laser marking is obtained by further adding one or more acrylic resins to one or more rubber reinforced thermoplastic resins and one or more thermoplastic norbornene resins, thereby completing the invention.
According to the present invention, new thermoplastic resin composition containing (A): one or more rubber reinforced thermoplastic resins (component (A)), (B): one or more acrylic resins (component (B)) and (C): one or more thermoplastic norbornene resins (component (C)) is provided.
The thermoplastic resin composition contains, preferably, 1 part to 95 parts by weight of component (A), 1 part to 90 parts by weight of component (B) and 1 part to 95 parts by weight of component (C), and more preferably, 10 parts to 80 parts by weight of component (A), 2 parts to 50 parts by weight of component (B) and 10 parts to 80 parts by weight of component (C)(wherein (A)+(B)+(C)=100 parts by weight).
Further, according to the present invention, there is provided a thermoplastic resin composition containing component (A), component (B), component (C) and (D): one or more styrenic resins other than those included in component (A) (component (D)).
The thermoplastic resin composition contains, preferably, 1 part to 95 parts by weight of component (A), 1 part to 90 parts by weight of component (B), 1 part to 95 parts by weight of component (C) and 1 part to 95 parts by weight of component (D) (wherein (A)+(B)+(C)+(D)=100 parts by weight).
Furthermore, the present invention provides shaped articles obtained by forming above-mentioned thermoplastic resin composition, and further provides shaped articles in which marking is made with laser beams.